I can't upgrade my computer at all!

[MEME_MAN]

Ok, so I have a computer made out of parts from random computers. I got a graphics card(R7 240) for my birthday, and as soon as I plugged it in, bam, computer doesn't work. Take it out, it works again. So I don't use the card. I bought a new processor, and same thing happened, doesn't work. I've looked everywhere, but i haven't seen anyone else with this problem. Please help.
Thanks!

 

[Barty1884]

Please post your full specs.

At first guess (based on the limit info), you may not have a PSU strong enough to support it.
Or, if you have an older motherboard (it would have to be quite old), your BIOS may not support an R7 240.

Again, full specs will help.

 

[MEME_MAN]

Please post your full specs.

At first guess (based on the limit info), you may not have a PSU strong enough to support it.
Or, if you have an older motherboard (it would have to be quite old), your BIOS may not support an R7 240.

Again, full specs will help.

So
Motherboard: Emachines T6126 i think
CPU: Intel Celeron 440
GPU: Intel 82945G Express Chipset Family (Intel GMA)
PSU:Bestec 300 Watts
RAM:4GB DDR2
HDD:320 GB Seagate and 160 GB WD

 

[drpower]

That system is about 10 years old, it may be time to retire it and start fresh.

http://www.cpubenchmark.net/cpu.php?cpu=Intel+Celeron+440+%40+2.00GHz